ZS without densitometer?

Discussion in 'Large Format' started by martin_kapostas|1, May 22, 2001.

  1. Hi all,

    <p>

    Is there any other way to work with ZS without densitometer ?
    Thanks

    <p>

    martin
     
  2. Well, you could always use the manufacturer's published data, which is obtained by using equipment and methodology far more accurate than most photographers have access to.
    As long as you're willing to use one of the recommended developers, Kodak issue development times for nearly all their B&W material to give 'N', 'N+1', and 'N-1' curves. See, for example, <a href="http://www.kodak.com/global/en/professional/support/techPubs/f32 /f32c.shtml#1090269>Tmax 100 characterisitics.
    Some of the world's finest photographs have been taken by photographers who totally ignored the zone system, and who openly admitted to knowing very little about sensitometry. Read the biography of Dorothea Lange for a case in point.
     
  3. "Oops, I'll try that again. Well, you could always use the manufacturer's published data, which is obtained by using equipment and methodology far more accurate than most photographers have access to.
    As long as you're willing to use one of the recommended developers, Kodak issue development times for nearly all their B&W material to give 'N', 'N+1', and 'N-1' curves. See, for example, Tmax 100 characterisitics.
    Some of the world's finest photographs have been taken by photographers who totally ignored the zone system, and who openly admitted to knowing very little about sensitometry. Read the biography of Dorothea Lange for a case in point.
     
  4. There are a couple of approaches you could take. One is to build your
    own densitometer using a spot meter. The plans are contained in Davis'
    "Beyond the Zone System." Secondly, you might take a look at Chris
    Johnson's book "The practical Zone System." He includes a series of
    tables showing film/exposure/development combinations. Many of these
    deviate from manufacturer's data and provide a starting point for your
    own testing. Third, I believe that Darkroom Innovations provides a
    testing service to determine your own personal film speed (see
    http://www.darkroom-innovations.com). I hope this helps.

    <p>

    ..................................
     
  5. Martin,
    Many of us have been practicing the Zone System, or variants thereof,
    for years without ever having once used a densitometer. I sometimes
    think that the densitometer actually gives less usable data since it
    doesn't take the paper you are using into consideration.

    <p>

    The basic method is this: You test film speed and development time by
    exposing the film and developing as you usually would, but instead of
    using the densitometer and the attendant number values, you
    make "proper proofs" on the paper of your choice.

    <p>

    A proper proof is generally considered to be one that renders the
    clear portions of the negative (film base+fog density) at maximum
    paper black with the least exposure. You find this by making a test
    strip from an unexposed, but developed and fixed (i.e. clear)
    negative, letting it dry completely and choosing the minimum exposure
    time needed to produce the maximum possible black.

    <p>

    In practice it's not quite that simple, since small differences in
    black can almost always be seen even past the point one would choose
    as a usable maximum black, however, you can safely choose one of
    these deep blacks and use that as your standard.

    <p>

    After this, you use the same lamp intensity, enlarger head to
    baseboard distance, f-stop and exposure time for all tests with this
    film unless the development time varies more than about 20%, in which
    case you need to determine a new "proper proofing time".

    <p>

    Now, all Zone System calibration tests can be done by proper proofing
    the test negatives. Zones values are there for you to see and
    visually evaluate, and differences in curves and gradation are easily
    seen.

    <p>

    For a good source on this, get "The New Zone System Manual" by Minor
    White et. al.

    <p>

    Sorry this is so long, but there is a lot to describing this, even if
    it is not that difficult in practice. Hope this helps. ;^D)
     
  6. I agree with Doremus. I started out trying to calibrate everything
    with a densitometer and was quickly becoming a tech head instead of an
    artist. I believe it is much more important for your negatives to
    print the way you want them to on the paper of your choice rather than
    arriving at some predetermined density. A more recent and excellent
    description of how to do all this without ever touching a densitometer
    is in Bruce Barnbaum's book, The Art of Photography: An Approach to
    Personal Expression. The book is a wealth of information and
    techniques that if followed will make your prints glow. His certainly
    do.

    <p>

    I have been a biologist and research scientist in aquatic biology for
    nearly 30 years,so I have some skills in dealing with technical stuff.
    I have read all the standard stuff on the Zone System (Adams, White,
    Picker, etc.) With that in mind, I have to tell you that Beyond the
    Zone System is way more information than most anyone would need and
    it is not the first book someone should read on the Zone System. I
    occasionally read it when I can't sleep.
     
  7. Hi Martin,

    <p>

    Doremus hit it right on the nail. In a general and non detailed
    explanation, this is how I approuch the ZS. First let me say that
    I am A self taught landscape photographer. From the moment I see a
    vista in front of me , to the moment I look at the final print, every
    thing in between is tied together.

    <p>

    As a starting point , I try to land close to my film's density
    threshold by simply reducing the manufactures (iso) rating in half.
    Secondly, I find max black of the paper I will be print on. This BTW,
    is the glue that binds the whole process together. The Proof. I place
    my unexposed and developed negative (B+F), in the neg. carrier. I
    project the light to the same print size I will be using.

    <p>

    I first burn a maxium black guide print. I mark the enlarger hieght
    and begin exposing independent time sequences. Another words if I
    want a 3,6,9,12,15 I expose each one at a time. I take these test
    prints and give them a couple of minutes in the microwave. I want
    that first shade of dark that matches my maxium black test print.

    <p>

    Now, I expose a negative at zone 1 at the 50% rating iso I mentioned
    above. I place in the enlarger and give it the numbers that gave me
    max black, minmun time. What I am looking for now is the first shade
    of black going the other way toward a lighter shade. If it is , then
    I keep that iso film speed, if not I tweek the iso one way our the
    other. Remember what I said about everythig in between. What I did
    here is place (sinc'd)my film's threhold along side my papers.

    <p>

    Lastly, for the real World zone 8. Using your same film and iso as
    before go out side, meter on a big fluffly white cloud (the way you
    visualise a be white fluffly cloud should) and expose it in zone 8. I
    expose about 4 or 5 negatives the same zone 8. I then develope each
    one at different times before and after the recommended time. I place
    these negatives in the enlarger using the same proof time I just
    created. Now when I turn on the lights and see the one that gives me
    my big fluffy white clouds.

    <p>

    Then Presto! I now have my normal Negative always using my same
    processing,paper size,film ect. What ever you point that 1 degree on
    you will feel confident that what you visualise is that zone , will
    be that way on the final print. Did I ever mention the word
    densitometer even once?
     
  8. Here is another good description how to do it without densitometer:

    <p>

    http://www.heylloyd.com/technicl/fishback.htm
     
  9. I think that one should at least attempt to obtain the film speed by
    finding the ASA so that a Zone 1 measures at 0.1 above film base plus
    fog. This requires a densitometer, and one can ask a lab, a friend, a
    professional, or someone to obtain this data. This, and the maximum
    black exposure time provides a good foundation on which to build. The
    remaining steps can be accomplished by evaluating and comparing
    exposures on paper at maximum black.

    <p>

    a) Determine "N" by finding the development time that gives a good
    Zone 8. (For me, this is where the texture, while not full, is
    detectable. The whitest portion of puffy clouds is probably close.)

    <p>

    b) Determine "N-1" by determining the development that makes a Zone 9
    have the apparent density on the print as a Zone 8 at "N". This can
    be accomplished by comparing test prints.

    <p>

    c) Determine "N+1" by determining the development time that makes a
    Zone 7 have the apparent density on the print as a Zone 8 at "N".

    <p>

    d) Etc.

    <p>

    I use a frosted piece of glass mounted on a black board with a 6"
    hole and place a "blue" daylight bulb behind this glass to achieve the
    different zones. Sometimes the light is placed well behind the
    frosted glass to obtain the lower zones.

    <p>

    So, I guess I recommend a workable compromise on this issue. Even if
    one has a densitometer, one should never depend solely on that device
    to obtain all development times. In my opinion, "N" always begins
    with a visual interpretation and decision of what they want for a Zone
    7 or a Zone 8. Thereafter, one uses the densitometer only as an aid
    to determine if the Zone 9 negative matches the Zone 8 in "b)" above,
    to determine if the Zone 7 matches the Zone 8 in "c)", and so on.
     
  10. It simply is not the negative that hangs on the wall. It is the
    print. For that reason you MUST make negatives that will print on the
    paper you wish to use. Also realize that black at grade 1 on a VC is
    not the same as black at grade 4. You need to have a mix of the
    emulsion on the paper and not be at either extreme. The negative
    needs all the information you require, but exactly where that falls
    on the scale will be determined how it prints on the paper. For these
    intertwined reasons, you simply create a negative to a predetermined
    scale of values and expect it to print how you want without including
    the paper in the scheme of things. Printing paper and the contrast,
    along with the look of the paper at each contrast, has a far greater
    impact on the image than slight changes in the negative. Besides, you
    are all the densitometer you need. You have to be able hold the
    negative up to an even light, like the blue sky, and be able to see
    anything you want to print. If not, then you have a problem at either
    end of the scale. Plus and Minus changes are never perfect, nor do
    they need to be. They help, but personal selection of values is not
    an exact science. Remember, Edward Weston didn't even use a light
    meter. So, you are already way ahead of the game.
     
  11. To suggest that one only needs to be able to see the detail that they
    require on the negative in order to obtain the photograph they want
    discounts the fact that the negative can retain more information than
    the paper is able to print. It's also necessary to match the detail
    (in the negative) that one requires on the final print to the paper
    that they've selected. I know that I've always had bad luck relying
    on paper grades to pull the proverbial rabbit out of the hat.

    <p>

    The zone system is an ingenious system to transfer the image onto a
    negative in a way that the photographer can best achieve his or her
    visualization of the final print. A densitometer is a useful tool
    that allows one to better and more easily accomplish this task.

    <p>

    As to Edward Weston, he used an emperical approach that relied on
    years of experience in the field taking how many thousands of shots in
    determining his exposure strategy. Using a light meter in conjunction
    with the zone system enables us to achieve a personal exposure
    strategy in far less time.
     
  12. Treaditional zone system testing is a pain, with or without a
    densitometer. Phil Davis' system as explained in his book "Beyond the
    Zone System" is far simpler and much more accurate. For approximately
    $30 The View Camera Store (formerly Darkroom Innovations) will do
    everything for you with whatever film (or films) you like. They send
    you five sheets of whatever film you wish to test, exposed with a 21
    step wedge. You develop the sheets for 4 minutes, 5 1/2 minutes, 8
    minutes, 11 minutes, and 16 minutes. You return the developed film to
    them and they take the readings with a densitometer, plug the
    readings into Phil Davis' plotter program, and send you the resulting
    information so that presto you have everything you need to use the
    zone system without the time, expense, and general hassle of old
    fashioned methods of testing. I'd strongly recommend letting them do
    most of the work for you so that, among other benefits, you don't
    have to worry about not having a densitometer.
     

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